Quantitative indices for an intracranial aneurysm and subarachnoid hemorrhage in early childhood: a case report

Background Intracranial aneurysms (ICA) rarely occur in children under 3 years of age. Little is known for neuroimaging parameters that predict survival and clinical outcomes of patients with ICA in early childhood. Case presentation A 2-year-old girl showed intracranial hemorrhage due to a rupture of aneurysm at the middle cerebral artery. Quantitative measurements of ischemic damages on the head computed tomography (CT) marked an extremely low score of 2 points with modified Alberta Stroke Program Early CT Score (mASPECTS). She died 15 days after admission. In publications from 2021 to 2022, we found 21 children who were under 3 years of age at onset of ICA. None of them died, but two of three patients who had mASPECTS scores 0–8 showed developmental delay and/or epilepsy as neurological complications. Conclusion Early CT findings are applicable for predicting survival and neurological outcomes of young children with intracranial hemorrhage. Supplementary Information The online version contains supplementary material available at 10.1186/s12883-022-03022-4.


Background
Intracranial aneurysm (ICA) is a rare condition in children under 3 years of age [1,2]. Infections, posttraumatic, and specific genetic conditions are more frequently associated with ICA and ICA-related brain hemorrhages in childhood than those in adults [3]. However, only a few reports have demonstrated details in neuroimaging features and clinical outcomes of patients with ICA in early childhood [4,5]. Two neuroimaging parameters, simplified gray matter attenuation-to-white matter attenuation ratio (sGWR) and modified Alberta stroke program early CT score (mASPECTS), are known to be useful for quantitatively analyzing parenchymal damages of the brain in children with cardiac arrest [6]. We thus asked whether these scoring systems might also provide critical values for the outcome of ICA in early childhood.
We herein report a young child who had a rupture of ICA at the middle cerebral artery (MCA) and characterize the neuroimaging feature of this patient in comparison with previously reported children under age 3 years.

Case presentation
A 2-year-and-8-month-old girl was referred to the previous hospital because of altered consciousness. A head computed tomography (CT) indicated the urgent neurosurgical intervention for the intracranial hemorrhage with a midline shift. On arrival to our hospital, spontaneous breathing was absent, and Glasgow Coma Scale was evaluated to be E1V1M1. The contrastenhanced CT in our hospital confirmed the hemorrhage *Correspondence: kaku.noriyuki.198@m.kyushu-u.ac.jp extending to the subarachnoid space and disclosed an aneurysm of 21 × 13 × 12 mm at the right MCA (Fig. 1). We applied quantitative measurements of the sGWR and mASPECTS (range 0-24) for her neuroimaging data (Fig. S1). The modified sGWR scored 1.13, while mASPECTS gained only 2 points, both suggestive of poor prognosis [6]. Although decompressive surgery was immediately performed, her systemic conditions became unstable with uncontrollable pulmonary edema. She died on the 15th day after admission. The panel sequencing for COL3A1, FBN1, TGFBR1, TGFBR2, and RNF213 excluded the diagnosis of Ehlers-Danlos syndrome, Marfan syndrome, Loeys-Dietz syndrome, and Moyamoya disease. Blood culture was negative throughout the treatment course. Systemic imaging studies excluded malformation of great arteries, renal cysts, and tumors.

Discussion
ICA in pediatric age accounts for 10-15% of the whole patient populations [13]. Patients under 3 years of age are extremely rare in prevalence [14,15]. While it is difficult to perform angiography for infants and young children during the critical period, pediatric patients with successful outcomes have been increasingly reported in recent years [3-5, 8, 11, 12]. Nevertheless, data have been less extensively analyzed for young children with unfavorable clinical courses. For this reason, the present case underscores the diagnostic value of neuroimaging findings for accurately detecting the ICA in early childhood.
In our previous study, lower scores (sGWR < 1.14 and mASPECTS < 20) were correlated with worse outcomes [6]. The present case showed low values of sGWR (1.13) and mASPECTS (2) on admission. Although further studies are required, these data may compensate insufficient prognostic values for survival and neurological outcomes of pediatric patients with intracranial hemorrhage.
Different patho-mechanisms have been considered to be involved in the development of ICAs in childhood and adults [1,2,4]. Childhood-onset ICAs are more frequently associated with trauma, infection, and particular genetic backgrounds than adult-onset ICAs [16]. In our patient, either the family information, past history, laboratory data or genetic analysis did not support evidence for common causes of ICAs. Thus, the patient was etiologically classified into the group of "idiopathic" ICA [1].
In conclusion, contrast-enhanced CT is a useful modality not only for detecting the source of hemorrhage, but Table 1 Summary of patients with intracranial aneurysms less than 3 years of age (reports in 2021-2022) 1 Age represents years (y) and months (m) 2 The mASPECTS scores were estimated and classified into the following three groups according to the presented images: L (low, 0-8), M (moderate, [9][10][11][12][13][14][15][16]